Interfacial reaction and electrical characteristics of Cu(RuTaNx) on GaAs: Annealing effects

This study elucidates the thermal stability and quasi ohmic contact characteristics of Cu(RuTaN_x) fabricated on a barrierless GaAs substrate. Cu(RuTaN_x) was prepared by cosputtering Cu, Ta, Ru, and N. The resistivity of the Cu(RuTaN_x)/GaAs structure annealed at 500 °C for 30 min was lower than that of the as-deposited structure, and the former was thermally stable up to 500 °C after 30 min of annealing. Further, the Cu(RuTaN_x)/GaAs structure exhibited electrical rectifying properties upon annealing at 550 °C for 10 min and revealed a quasi ohmic contact, as determined by the circular transmission line model (CTLM). The formation of quasi ohmic contact is further confirmed by transmission electron microscopy and energy dispersive X-ray spectroscopy.     

Theoretical rate coefficients for the reaction of methyl radical with hydroperoxyl radical and for methylhydroperoxide decomposition

The kinetics of the CH₃ + HO₂ bimolecular reaction and the thermal decomposition of CH₃OOH are studied theoretically. Direct variable reaction coordinate transition state theory (VRC-TST), coupled with high level multireference electronic structure calculations, is used to compute capture rates for the CH₃ + HO₂ reaction and to characterize the transition state of the barrierless CH₃O + OH product channel. The CH₂O + H₂O product channel and the CH₃ + HO₂ → CH₄ + O₂ reaction are treated using variational transition state theory and the harmonic oscillator and rigid rotor approximations. Pressure dependence and product branching in the bimolecular and decomposition reactions are modeled using master equation simulations. The predicted rate coefficients for the major products channels of the bimolecular reaction, CH₃O + OH and CH₄ + O₂, are found to be in excellent agreement with values obtained in two recent modeling studies. The present calculations are also used to obtain rate coefficients for the CH₃O + OH association/decomposition reaction.     

Quantum Wave Packet Studies on F ＋ HBr Reaction

IntroductionA series of reactions of fluorine atoms with hydro-gen halidesF HCl HF Cl (1)(ΔH—00=-137·10 kJ/mol)F HBr HF Br (2)(ΔH—00=-202·73 kJ/mol)F HI HF I (3)(ΔH—00= -270·45 kJ/mol)belongs to the prototypical heavy-light-heavy reactionsa     

High-performance copper alloy films for barrierless metallization

In this study, we observe useful properties of V_1.1- and V_0.8N_0.4-bearing copper (Cu) films deposited on barrierless silicon (Si) substrates by a cosputtering process. The Cu_98.8(V_0.8N_0.4), or Cu(VN_x) for brevity, films exhibit low resistivity (2.9 μΩ cm) and minimal leakage current after annealing at temperatures up to 700 °C for 1 h; no detectable reaction occurs at the Cu/Si interface. These observations confirm the high thermal stability of Cu(VN_x) films. Furthermore, since these films have good adhesion features, they can be used for barrierless Cu metallization.